1. Field of the Invention
The present invention relates to an aluminum alloy scrap melting process for melting aluminum alloy scraps such as aluminum alloy chips, aluminum alloy splinters, etc., and an apparatus for carrying out the process.
2. Prior Art
As a conventional aluminum alloy scrap melting process, there has been proposed a melting process comprising introducing scraps or chips into a vortex flow generated in molten metal which flows into a material introduction portion. On the other hand, an apparatus for generating a vortex flow in molten metal is known as disclosed in Unexamined Japanese Patent Publication (Kokai) Hei-1-132724, Hei-2-232323, Hei-3-120322, or the like.
The point common to the above Publications is as follows. That is, molten metal flows within a furnace so as to circulate, a round funnel-shaped vortex chamber is formed in a part of a passage of the molten metal, a vortex is generated as the molten metal is led from an upper port of the vortex chamber to a lower port of the vortex chamber, and aluminum alloy scraps or chips are therefore introduced into the furnace at the upper port of the vortex chamber. In the Publication Kokai Hei-1-132724, the circulation of the molten metal is performed by a molten metal stirring pump. In the Publication Kokai Hei-2-232323, the circulation of the molten metal is performed by an induction coil which is provided in the rear of an inclined portion which is provided so as to rise from a lower portion of the vortex chamber in the bottom of the furnace. In the Publication Kokai Hei-3-120322, the circulation of the molten metal is performed by an electromagnetic stirrer which is provided so as to be movable from the lower side of the vortex chamber to the upper side of the vortex chamber.
In the above-mentioned Publications, however, a difference in level is given to the circulating molten metal so that the molten metal can be poured into the vortex chamber from above and can be discharged from the lower of the vortex chamber. Accordingly, there arises a problem that a large-capacity electromagnetic stirrer is required. Further, as described above, the vortex chamber is formed to a funnel shape. Accordingly, there arise other problems, for example, that not only the structure of the inside of the furnace becomes complex but high-grade accuracy in finished size is required at the time of construction of the furnace so that a vortex can be generated securely relative to the flow rate of the molten metal.